2. Field of the Invention:
This invention relates to cameras having digital controls of shutter time, and more particularly to a coordinating control system for such camera suited to time exposures.
3. Description of the Prior Art:
In the conventional cameras having digital controls of shutter time, the discriminating means for selectively setting the bulb exposure mode and the automatic exposure mode is made to sense which mode is selected before a camera release is actuated. Where the automatic exposure mode is set, therefore, after the power switch is thrown, the discriminating means checks the automatic mode setting to render such coordinating control effective that the front curtain of the shutter is actuated to run down in response to the production of a release actuating signal, then the count start switch is opened, and, in a time interval dependent upon the automatic shutter time control means from the time of opening of the count start switch, an actuating signal is then produced to close the shutter as the tail curtain runs down. On the other hand, where the bulb mode is set, after the power switch is thrown, the bulb mode setting is checked by the discriminating means to render another coordinating control effective such that after a desired time interval after the running down movement of the front curtain has passed, when the release button is released from the force depressing it down, the electromagnet controlling the latching operation of the tail curtain is de-energized.
An object of the present invention is to provide a novel method of checking to determine which of the automatic and bulb exposure modes is selected after an actuation of release is initiated. When the discriminating means is fed with a signal soon after the initiation of a release actuation, the automatic exposure mode is set. On the other hand, the bulb mode is set by the discriminating means when no signal is fed thereto even after a predetermined time has passed from the time of initiation of the release actuation.
Another object of the present invention is to provide a control system for a camera capable of preventing failure of taking exposures as the release actuating signal is not produced soon after the completion of each cycle of film winding operation despite the variation of magnitude of the force depressing the release button which results in opening followed by closing the latter at a time during a continuous succession of frame exposures.